It is also impossible to mark the message as unread or read. For instance, this message (check attachment).
How shall I address this incident?
Regards,
Carlos Dourado
[hr]
When I was trying to include more info such as Firefox version, I realized that there must a cache issue of some sort, as the messages which are not shown seem to have been already deleted by other device.
I opened a new window, and forced a refresh, but to no avail… those zombie messages are still there.
For the record, issue occurred with Firefox 58.02 and Window 10.